Facing an issue with Sencha Cmd

Hi,

I'm trying to build production instance using sencha cmd. But, build is getting failed and throwing below error.

BuildFailed.jpg

Sencha Cmd version i'm using - 4.0.4.84, ExtJS version : 4.2.1

I've tried with different cmd version - 4.0.2.67, but still getting same error.

Am i missing anything? please help me.

Thanks in advance